This invention relates to tufting machines and is more particularly concerned with a mechanism for effecting longitudinal displacement of a needle bar of a tufting machine to adjust the position thereof for purposes of pattern control.
A known mechanism for effecting longitudinal positional adjustment of a needle bar of a tufting machine comprises a cam/cam follower arrangement which is connected to the bar so as to act, during use of the machine, to subject the bar to a sequence of movement in both longitudinal directions thereof, such sequence being dictated by the shape of the surface of the cam which the cam follower is constrained to follow. With this known construction however a high degree of operating precision cannot be ensured due to lost motion arising from clearances in the mechanism whereby it is difficult to achieve accurate following of the cam surface and thus satisfactory pattern control especially in the case of high speed fine gauge tufting machines.